Solve for $x$ and $y$ using substitution. ${x-2y = 12}$ ${x = y+5}$
Since $x$ has already been solved for, substitute $y+5$ for $x$ in the first equation. ${(y+5)}{- 2y = 12}$ Simplify and solve for $y$ $y+5 - 2y = 12$ $-y+5 = 12$ $-y+5{-5} = 12{-5}$ $-y = 7$ $\dfrac{-y}{{-1}} = \dfrac{7}{{-1}}$ ${y = -7}$ Now that you know ${y = -7}$ , plug it back into $\thinspace {x = y+5}\thinspace$ to find $x$ ${x = }{(-7)}{ + 5}$ ${x = -2}$ You can also plug ${y = -7}$ into $\thinspace {x-2y = 12}\thinspace$ and get the same answer for $x$ : ${x - 2}{(-7)}{= 12}$ ${x = -2}$